CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Apr. 03, 2020	Mar. 29, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 115	$ 189
Foreign currency translation adjustments	(74)	10
Unrecognized loss on derivative instruments	(42)	(15)
Pension adjustments	1	0
Total other comprehensive loss, net of taxes	(115)	(5)
Comprehensive income attributable to Leidos common stockholders	$ 0	$ 184